Surgical Instrument With Flexible Drive Mechanism

ABSTRACT

A drive mechanism for use with a surgical instrument includes a rotatable drive member, a crank operatively coupled to the drive member; a clutch operatively coupled to the crank, wherein rotational motion of the drive member causes oscillating movement of the clutch; and a gear rotatably coupled to the clutch, wherein the oscillating movement of the clutch causes rotation of the gear. The drive mechanism may further include a gear configured to engage a linear member. The crank may include a pin extending distally therefrom. The clutch may include a slot dimensioned and configured to receive a pin of the crank.

BACKGROUND

1. Technical Field

The present invention relates to surgical instruments and moreparticularly, to an endoscopic surgical instrument having a flexibledrive mechanism.

2. Background of Related Art

Articulating surgical instruments are well-known in the art. Surgeonstypically use articulating instruments to reach areas out of line withthe entry axis of the surgical instrument. Ordinarily, articulatingsurgical instruments transmit energy along a longitudinal axis of theinstrument, and do not effectively transmit large amounts of energy whenthe end effector is articulated at sharp angles. Surgical instrumentsthat use high force/low velocity methods often require physically largecomponents. These physically large components are usually quite rigidand are not easily bent.

The operation of current articulating surgical instruments involves themovement of a rod or a long flexible metal strip actuator around a bend.The use of such structural elements leads to, among other things,friction and buckling. These adverse consequences are normally minimizedby restricting the maximum bend angle of surgical instruments toapproximately 45 degrees.

For instance, U.S. Pat. No. 5,381,943 to Allen et al. discloses anendoscopic surgical stapling instrument comprising a pivotable staplehead assembly mounted on the distal end of a support tube. Theinstrument includes a handle assembly and a saddle-shaped actuatorslidably mounted thereon for controlling the pivotal movement of thestaple head assembly. An articulation driver is mounted inside thesupport tube. The articulation driver is formed by an elongated thinflat rod. In operation, the saddle-shaped actuator moves a slide membercoupled to a driver coupling member to operate the articulation driver.The articulation driver pivots the stapling head assembly in response tomovement of the saddle-shaped actuator. The staple head assembly can bearticulated to angles of 15, 30, 45 and 60 degrees relative to thesupport tube.

In light of current articulating surgical instruments shortcomings, itwould be beneficial to provide a surgical instrument capable of bendingat angles of at least 90 degrees and transmit the energy required tooperate a surgical tool, such as an end effector. It would also bedesirable to provide a surgical instrument capable of transmitting largeamounts of force at very large angles using simple and reliablestructural elements. Therefore, a need exists for a reliable surgicalstapling device and a mechanism for use therewith that will allow a userto operate a surgical tool at angles of at least 90 degrees relative tothe entry axis of the surgical instrument.

SUMMARY OF THE INVENTION

The present application discloses a surgical instrument and a mechanismfor use therewith capable of articulating at least 90 degrees withrespect to a longitudinal axis defined therealong, and applying theforce necessary to operate a surgical tool disposed at a distal endthereof. The mechanism includes a drive member having proximal anddistal ends, a crank mechanism operatively connected to the distal endof the drive member, a clutch coupled to the crank mechanism, and a gearrotatable about a central axis and configured to engage a linear driver.The drive member is rotatable and may be flexible. A handle portionattached to the proximal end of the drive member may provide thenecessary motion to rotate the drive member. Many types of handleassemblies may be employed to provide rotational motion to the drivemember. The rotational motion of the drive member rotates a crankmechanism.

The crank mechanism converts the low torque rotational motion of thedrive member into a high torque rocking motion of just a few degrees.The crank mechanism may include a rod member and a pin extendingdistally thereof. The pin itself undergoes a circulating and rockingmotion as the drive member rotates. The pin is configured to interactwith a slot of the clutch.

The clutch transforms the rocking motion of the crank mechanism intorotational motion, thereby rotating a gear connected thereto. The gearmay be substituted for a sprocket or a similar driver known in the art.The rotational motion of the gear causes the linear driver to translate.

The linear driver is operatively connected to the gear. The lineardriver may be comprised of a rack, a chain or a similar driver. As thegear rotates, the linear driver translates to operate a surgical tool.The instrument hereinabove described has a high mechanical advantage.

These and other features of the mechanism of the subject applicationwill become more readily apparent to those skilled in the art from thefollowing detailed description of the embodiments of the device taken inconjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the surgical instrument and the mechanism for usetherewith of the present disclosure will be described hereinbelow withreference to the drawings wherein:

FIG. 1 is a perspective view of a surgical instrument constructed inaccordance with an embodiment of the present disclosure;

FIG. 2 is an side longitudinal cross-sectional view of a portion of thesurgical instrument of FIG. 1;

FIG. 2 a is a perspective cut away view of a portion of the surgicalinstrument of FIGS. 1 and 2;

FIG. 3 is side longitudinal cross-sectional view of a portion of apneumatic powered surgical instrument constructed according to anotherembodiment of the present disclosure;

FIG. 4 is a perspective view of a drive mechanism constructed inaccordance with an embodiment of the present disclosure;

FIG. 5 is an exploded perspective view of the drive mechanism of FIG. 4;

FIG. 5A is a perspective view of a portion of a drive mechanismaccording to an embodiment of the present disclosure;

FIG. 5AA is a top cross-sectional view of a portion of the drivemechanism of FIG. 5A, taken along section lines 5AA-5AA of FIG. 5A;

FIG. 5AB is an exploded perspective view of the portion of the drivemechanism of FIG. 5A;

FIG. 5AC is a top cross-sectional view of the drive mechanism of FIG. 5Ain a first position;

FIG. 5AD is a top cross-sectional view of the drive mechanism of FIG. 5Aduring movement of a gear in a first direction;

FIG. 5AE is a top cross-sectional view of the drive mechanism of FIG. 5Aduring movement of a gear in a second direction;

FIG. 5B is a perspective view of a drive mechanism according to anembodiment of the present disclosure;

FIG. 5BA is a top cross-sectional view of the drive mechanism of FIG. 5Bin a first position, taken along section lines 5BA-5BA of FIG. 5B;

FIG. 5BB is a top cross-sectional view of the drive mechanism of FIG. 5Bduring movement of a gear in a first direction;

FIG. 5BC is a top cross-sectional view of the drive mechanism of FIG. 5Bduring movement of a gear in a second direction;

FIG. 6 is an exploded perspective view of a portion of the surgical toolof the surgical instrument of FIG. 1;

FIG. 7A is a top cross-sectional view of the drive mechanism of FIGS. 4and 5 in a first position, taken along section lines 7A-7A of FIG. 4;

FIG. 7B is a top cross-sectional view of the drive mechanism of FIG. 7Aduring movement of a gear in a first direction; and

FIG. 7C is a top cross-sectional view of the mechanism of FIG. 7A duringmovement of a gear in a second direction.

DETAILED DESCRIPTION

Embodiments of the presently disclosed surgical instrument and themechanism for use therewith are now described in detail with referenceto the drawings, in which like reference numerals designate identical orcorresponding elements in each of the several views. As used herein, theterms “distal” refers to that portion of the surgical instrument, orcomponent thereof, farther from the user while the term “proximal”refers to that portion of the component thereof, closest to the user.

Referring initially to FIG. 1, a surgical instrument in accordance withan embodiment of the present disclosure is referred to in the figures asreference number 100. Briefly, surgical instrument 100 is configured toclamp body tissue and apply a plurality of surgical fasteners to thebody tissue during laparoscopic or endoscopic procedures. In particular,surgical instrument 100 is capable of transmitting the force necessaryto operate a surgical tool attached to the distal end thereof at anglesof at least 90 degrees relative to a longitudinal axis defined by thesurgical instrument 100 and includes a drive mechanism described indetail below.

The drive mechanism disclosed in the present disclosure may be used withother types of surgical instruments. Thus, for example, an instrumentparticularly suited for open surgery can be used. Alternatively, aninstrumented suited for laparoscopic or endoscopic surgery may be used.Examples of laparoscopic and endoscopic instruments are disclosedrespectively in U.S. Pat. Nos. 5,014,899 and 7,128,253, the entirecontents of each is incorporated herein by reference. While the drivemechanism will be primarily discussed in the context of applyingstaples, it can also be employed in connection with a clip applier, acutter or any other suitable surgical instrument.

As seen in FIG. 1, surgical instrument 100 includes a handle portion112, an elongated body portion 114 extending distally from handleportion 112, and a tool assembly 116 connected to a distal end of bodyportion 114. Elongated body portion 114 may be flexible. Handle portion112 supplies high velocity, low torque rotation to a shaft throughelectromechanical means or any other suitable means known in the art. Anumber of handle assemblies may be employed with surgical instrument100.

As illustrated in FIGS. 2 and 2 a, handle portion 112 includes anelongated barrel section 118 and a handle gripping section 120, asdescribed in U.S. Pat. No. 5,954,259, the entire contents of which isincorporated herein by reference.

A motor assembly 122 is disposed within the barrel section 118 and isoperatively coupled to drive member 311. Alternatively, handle portion112 can include gear box operatively connected to motor assembly 112 toincrease or decrease the rotary motion supplied by motor assembly 112.In this embodiment, the gear box is operatively coupled to drive member311.

Referring to FIG. 3, in an alternative embodiment, handle portion 212provides rotational motion via pneumatic means, as described in U.S.patent application Ser. No. 10/528,851, the entire contents of which isincorporated herein by reference. In this embodiment, handle portion 212includes a rotary pneumatic drive assembly 200 housed within handleportion 212 that rotates a shaft 255. Shaft 255 is operatively connectedto drive member 311. In addition, handle portion 212 includes a fixedhandle 265 formed like a pistol grip to enhance manipulation of thesurgical instrument 210 as needed during surgery. Handle portion 212 mayalso include a movable handle actuator 260 (shown in phantom) that ismovable relative to fixed handle 265 for actuating tool assembly 216.

Referring now to FIGS. 4 and 5, mechanism 300 has a drive member 311operatively connected to a crank mechanism 312, a clutch 313 configuredto interact with crank mechanism 312, a fastening device 321interconnecting crank mechanism 312 and a gear 314, and a linear driver315 configured to engage gear 314. Drive member 311 may be disposed inmechanical cooperation with either to motor assembly 122 or pneumaticdrive assembly 200. One skilled in the art, however, will recognize thatother kinds of driving devices may be used with drive mechanism 300. Inaddition, drive member 311 may be made of a flexible material capable ofbending at least 90 degrees with respect to an axis “X”.

Drive member 311 has a distal end 317 and a proximal end 316. Proximalend 316 of the drive member 311 is operatively connected to a handleportion 112, 212 or other suitable source of rotational motion. Asdiscussed hereinabove, a number of handle portions may be employed torotate drive member 311. Distal end 317 of the drive member 311 isoperatively connected to a crank mechanism 312. Crank mechanism 312includes a rod member 318 and a pin 319 extending distally therefrom.Pin 319 extends from a location offset from the center of a distal endsurface 318 a of rod member 318, and has a cylindrical shape. Othersuitable shapes, as recognized by those skilled in the art, may be usedfor pin 319. Additionally, pin 319 is positioned within a slot 320 of aclutch 313.

Clutch 313 is operatively coupled to crank mechanism 312, and includes asubstantially annular space 323 defined therein, a slot 320 dimensionedfor receiving pin 319, and a gear 322 positioned in annular space 323.Gear 322 can be a toothed wheel. Annular space 323 is dimensioned andconfigured to receive gear 322. Inner wall 325 of clutch 313 definesannular space 323. A protrusion 324 extends from inner wall 325 to theperiphery of gear 322. A fastening member 321 interconnects clutch 313and a gear 314.

With reference to FIGS. 5A, 5AA, and 5AB, in another embodiment, clutch313 includes first and second protrusions 326 a, 326 b facing oppositedirections. First and second protrusions 326, 327 are selectivelymovable to engage gear 322. In one embodiment, first protrusion 326 hasan engagement section 326 a and a coupling section 326 b. Likewise,second protrusion 327 may include an engagement section 327 a and acoupling section 326 b. To facilitate movement of protrusions 326 a, 326b, protrusions 326 a, 326 b are operatively coupled to knobs 328, 329,respectively. Specifically, knob 328 is disposed in mechanicalcooperation with coupling section 326 b of first protrusion 326 whereasknob 329 is disposed in mechanical cooperation with coupling section 326b of second protrusion 326. At least a portion of coupling sections 326b, 327 b are disposed in bores 330, 331 of clutch 313. Bores 330, 331are adapted to receive at least a portion of coupling sections 326 b,327 b. Each bore 330, 331 includes a detent 330 a, 331 a for releasablysecuring first and second protrusions 326, 327 in place. As will bediscussed in detail below, during operation, first protrusion 326 allowsdistal translation of linear drive 315 while second protrusion 327allows proximal translation of linear drive 315 by selectivelyinteracting with gear 322, as shown in FIGS. AC, AD, and AE.

Returning to FIGS. 4 and 5, gear 322 is operatively associated with gear314. In turn, gear 314 is adapted to engage a linear driver 315 andconfigured to rotate about a central axis “Y.” Linear driver 315 isdesigned to drive a cam sled 428 of tool assembly 116 (see FIG. 6) andmay be formed by a rack, a chain or other suitable apparatus. Gear 314may be replaced by a sprocket or any other suitable apparatus. Asdiscussed above, surgical instrument 100 may be used with any suitablearticulating or bendable tool assembly.

Alternatively, as shown in FIG. 5B, gear 322 can directly engage lineardriver 315. In this embodiment, gear 322 extends beyond the boundariesof clutch 313. During operation, the portion of gear 322 clutch 313 thatis not covered by clutch 313 engages linear driver 315. As it will beexplained in detail below, the rotation of gear 322 causes the distalmovement of linear driver 315. This distal movement, in turn, actuatestool assembly 116.

As seen in FIG. 6, tool assembly 116 includes, for example, a cartridgeassembly 420, as described in U.S. Pat. No. 5,651,491, the entirecontents of which is incorporated herein by reference. Cartridgeassembly 420 includes plurality of slots 421 that support acorresponding number of surgical staples 424, a plurality of staplepushers or ejectors 426 adapted and configured to eject the staples fromthe slots when acted upon by a staple driving force, and an actuationsled 428 which is driven by linear driver 315 to translate throughcartridge 420 in a longitudinal direction to transmit a staple drivingforce to the ejectors.

With reference to FIGS. 7A-7C, in operation, either motor assembly 122or rotary pneumatic drive assembly 200 rotate drive member 311. Therotation of drive member 311, in turn, produces rotational motion ofcrank mechanism 312, in the direction shown by arrow “A.” The crankmechanism 312 converts the high speed, low torque rotational motion ofthe drive member 311 to a high torque rocking or oscillating motion ofjust a few degrees. Since pin 319 is radially offset from the center ofdistal end surface 322 of rod member 318, the rotation of rod member318, in the direction shown by arrow “A,” initially causes the rockingmotion of pin 319 in the direction shown by arrow “B1”. As pin 319begins to move, clutch 313 rotates clockwise, as illustrated by arrow“CW”. While rod member 318 continues to rotate, pin 319 continues tomove in the direction shown by arrow “B2” and clutch 313 continues torotate clockwise, as shown by arrow “CW.” The continued rotation of rodmember 318 eventually causes pin 319 to move in the direction shown byarrow “B3.” At this point, the continuing motion of pin 319 causesclutch 313 to rotate counterclockwise, as shown by arrow “CCW.” Therotation of clutch 313 causes the corresponding rotation of gear 322.The rotation of clutch 313 eventually causes the counterclockwiserotation of gear 322, as shown by arrow “D”. The rotary motion of firstgear 322 causes the rotation of gear 314, as shown by arrow “E.” Inresponse to the rotational motion of gear 314, linear driver 315 movesaxially with an extremely high force, as illustrated by arrow “F.” Aslinear driver 315 advances, actuator sled 428 translates to operate toolassembly 116. Alternatively, linear driver 315 may be translateddirectly by gear 322, as illustrated in FIGS. 5BA, 5BB, and 5BC.

In any event, the translation “F” of linear driver 15 produces a forcestrong enough to operate tool assembly 116 of surgical instrument 100 atangles of at least 90 degrees relative to longitudinal axis “X”. Themethod hereinabove described provides a mechanical advantage of at least100:1. Mechanism 300, however, can be used for other methods ofoperation. For instance, mechanism 300 may be utilized to retractactuation sled 428 to its original position after firing surgicalinstrument 100.

With reference to FIGS. 5AC, 5AD, and 5AE, an operator can retract camsled 428 by proximally moving linear driver 315 by using embodimentshown in FIG. 5A. To translate linear driver 315 proximally, a user mayengage second protrusion 327 and disengage first protrusion 326.Thereafter, motor assembly 122 or rotary pneumatic drive assembly 200rotates drive member 311. In response thereto, crank mechanism 312rotates in the direction shown by arrow “A” and converts the high speed,low torque rotational motion of drive member 311 to a high torquerocking or oscillating motion of just a few degrees. In particular, therotation of rod member 318 initially causes the rocking motion of pin319 in the direction indicated by arrow “G1.” As pin 319 moves, clutch313 rotates clutch counterclockwise, as illustrated by arrow “CCW.”While rod member 318 continues to rotate, pin 319 continues to move inthe direction shown by “G2” and clutch 313 continues to rotatecounterclockwise, as shown by arrow “CCW.” The continued rotation of rodmember 318 eventually causes pin 319 to move in the direction shown byarrow “G3.” At this point, the continuing motion of pin 319 causesclutch 313 to rotate clockwise, as shown by arrow “CW.” The rotation ofclutch 313 causes the corresponding rotation of gear 322, as shown byarrow “H.” The rotary motion of first gear 322 causes the rotation ofgear 314, as shown by arrow “I.” In response to the rotational motion ofgear 314, linear driver 315 moves proximally, as illustrated in by arrow“J.” The proximal translation of linear driver 315 retracts actuatorsled 428 to its original position.

The applications of the surgical instrument 100 and the methods of usingthe same discussed above are not limited to stapling instruments used toattach body tissues, but may include any number of further surgicalapplications. Modification of the above-described surgical instrumentand methods for using the same, and variations of the disclosure thatare obvious to those of skill in the art are intended to be within thescope of the claims. For example, other varieties of one way clutchesmay be employed with surgical instrument 100 or mechanism 300.

1-20. (canceled)
 21. A drive mechanism for a surgical instrument,comprising: a drive member; a crank operatively coupled to the drivemember and including a pin extending distally from a location offsetfrom a center of the crank; a clutch operatively coupled to the crankand configured to convert a rotary movement of the drive member intomovement of the clutch; and a linear driver configured to movelongitudinally in response to movement of the clutch.
 22. The drivemechanism of claim 21, further comprising a gear rotatably coupled tothe clutch, wherein the movement of the clutch causes rotation of thegear.
 23. The drive mechanism of claim 22, wherein the gear isconfigured to engage the linear driver to impart longitudinal motionthereto.
 24. The drive mechanism of claim 23, wherein the rotation ofthe gear causes distal longitudinal motion of the linear driver when thegear and the linear member are engaged with each other.
 25. The drivemechanism of claim 21, wherein a longitudinal motion of the lineardriver actuates a surgical tool.
 26. The drive mechanism of claim 21,wherein the clutch includes a slot dimensioned and configured to receivethe pin.
 27. The drive mechanism of claim 26, wherein a movement of thepin within the slot converts the rotary movement of the drive memberinto an oscillating movement of the clutch.
 28. A surgical instrument,comprising: a handle portion; an elongate portion extending from thehandle portion; an end effector operatively coupled to the elongateportion; a drive mechanism operatively associated with the handleportion, the drive mechanism including: a drive member; a crankoperatively coupled to the drive member and including a pin extendingdistally from a location offset from a center of the crank; a clutchoperatively coupled to the crank, wherein the crank is configured toconvert a rotary movement of the drive member into movement of theclutch; and a linear driver configured to move longitudinally inresponse to the movement of the clutch, wherein the longitudinal motionof the linear driver actuates the end effector.
 29. The surgicalinstrument of claim 28, further comprising a gear rotatably coupled tothe clutch, wherein the movement of the clutch causes rotation of thegear.
 30. The surgical instrument of claim 29, wherein the gear isconfigured to engage the linear driver to impart longitudinal motionthereto.
 31. The surgical instrument of claim 28, wherein the rotationof the gear causes distal longitudinal motion of the linear driver whenthe gear and the linear member are engaged with each other.
 32. Thesurgical instrument of claim 28, wherein the clutch includes a slotdimensioned and configured to receive the pin.
 33. The surgicalinstrument of claim 32, wherein a movement of the pin within the slotconverts the rotary movement of the drive member into an oscillatingmovement of the clutch.
 34. The surgical instrument of claim 28, whereinthe drive member is configured to rotate upon actuation of the handleportion.